Gun perforator



Aug. 8, 1950 A, E HAMBLY 2,517,560

GUN PERFQRATOR Filed Jan. 15, 1945 /lllll 11111.

Patented Aug. `8, 1950 A i 'UNITED STATES PATENT OFFICE `N GUN PERFoBAToR Allen E. Hambly, Huntington Park, Calif., assignor to Byron Jackson Co.,\Vernon, Calif., a

corporation of Delaware h Application January 15, 1945, Serial No. 572,799 4 Claims. (Cl. 164-45! 'I'his invention relates generally to gun perfowhich is connected the upper end of a flexible,

rators for perforating well casing and the like, and is directedparticularly to an improved system and apparatus for` firing such guns.

A general object of this invention isto provide an improved iiring system for gun perforators.

Another object is to provide a. firing system for gun perforators wherein a cartridge containing `an explosive charge is positioned in front of each bullet, and each explosive charge is individually,` 10

ignited electrically. f

A still further object is to provide a novel cartridge adapted to be inserted into the muzzle of the gun boreof a gun perforator.

A still further object is to provide a tiring sys- 15 tem for gun perforators which is of simple and economical construction and which can be readily assembled in a multi-shot gun perforator.

The manner in which the foregoing and other objects are attained will be apparent from the following detailed description of one embodiment and several modifications thereof, reference being had to the accompanying `drawings wherein: Fig. 1 is a view, partly in elevation 'and partly in longitudinal section, of the upper `portion of a g5 gun chambers 3. The apertures 2 are preferably 35 arranged in angularly oil'set relation to each other, and as herein shown, adjacent sockets are disposed at right angles to each other., ,f A cable head `I is attached to the upper end of the body I in any suitable manner, such, for ex- 40 ample, as by cap screws 5 countersunk in recesses in the head. `An axially extending socket 6 is provided in the head for the reception oi a sleeve member 1 attached to the lower end of a cable 8, the sleeve member 1 being releasably re- 45 tained in the socket by means such as a snap ring 3. l

The cable 8, in addition to its function of supporting the gun while in use, also contains an insulated conductor for transmitting electric 50` current to the gun ilrlng mechanism. An elecinsulated conductor cord I3. The construction of the cable head and the electrical connection just described is described in the copending application of Raymond D. Elliott, Serial No.

558,581, led October 13, 1944.

I The conductor cord I3 is preferably wrapped `helically around the gun body I so as to pass over the muzzle ends of the gun chambers 3, and the gun body is preferably provided with a helical groove Ia to accommodate the cord;

Referring now to the gun chambers 3 and their mounting in the apertures 2 in the gun body I, it will be observed K.that each chamber is supported at opposite ends thereof in seats formed in the walls of the body, the aperture 2 supporting the forward end of the chamber, and the rearward end being supported by a seat I4. Rearward recoil movement of the chamber is 20 limited by the frusto-conical seat I5 at the base of the seat I4. 'I'he chamber is releasably retained in its socket in the body by a snap ring Ii engaging an interial groove in the wall of the aperture 2 and abutting a shoulder I l` formed on the chamber. If desired, the chamber may be loosely mounted in the socket to permit limited recoil movement thereof between engagement of` the shoulder I 1 with the snap ring I Ii and engagementof the` rearward end of the chamber with the seat I5. An opening I8 may also be provided in the body I at the rear of the chamber toadmit well fluid into the `narrow clearance space between the chamber and the seat I5, and thus etl'ect a iluid recoil snubbing action to cushion therimpact of the chamber against the body when the bullet is discharged; Theconstruction of the chamber and its mounting in the body are described and claimed in the copending application of Raymond D. Elliott, Serial No. 527,110, led March 18, 1944, now PatentNo. 2,402,153, granted June 18, 1946.

Each gun chamber 3 is bored axially from the front end to a. point spaced from the rear end to provide theusual gun bore 20 for receiving a bullet 2l and a propellent powder charge 22. A disk or washer 22 of lead or other suitable plastic sealing material may, if desired, be interposed between the rear end of thebullet and the powdercharge. l

Itwill beparticularly noted that there is no primer or explosion initiator directly associated with the propellent powder charge 22 to initiate I trode III is attached to the cableand extends into the explosion by ignition, is customary in gun an insulated socket II in the head I to` contactV an insulated conductor pin I2 in the head, the

head of the pia` lz` forming a bracing was perforators. Instead, I prefer to explode the charge 22 by the detonation of a charge of explosive in iront of thebullet, in the manner mating socket member 31 end 33 adapted to iit` strong enough to withstand externaljiuid presi sures. A suitable sealing element 38a or sealing `increase thevlengths of taught `in `the aforementioned copending application Serial No. 558,581. `As set forth therein, this method of exploding the propellent charge causes a more rapid rate of combustion of the powder `charge into gases, and producing an effect which is more akin to detonation than to explosion. In this mannen: a higher `muzzle velocity ofzthe bullet is` attained. Referring to' Flggl of the drawing, explosion of the propellent charge 22 is effected by detona-` tionv of an electrically fired cartridge, generally designated 25, which is inserted into thexiiuzzle` of the bore 20. The cartridge may assume vari ous forms, specific examples of which are shown inFigs. 2 to 5.

In the form shown in Fig. 2, the cartridge comprises `a thin metallic cup-shaped case V26 lof brass or other suitable material, which fits snugly in the gun bore and the outer end of which is provided with a flanged-head 21 at its outer end adapted to seat against: a shoulder formed by a counter-bore 29 atthe muzzle end of the gun bore cured by its head 21 to the conductor cord I3 which,` Lin this construction, includes `a sheath I3a and a conductor I3b. If it is desired to arrange the cartridges for series `connection, the conductor |35 isbrokenat intervals and the ends thus formed directed `into g the case 26 through small openings` inthe head 21. The conductor s ends `within the case are suitably connected `by a p lament 30 andthe case nlled with an explosive s charge 3|, preferably a `high explosive of -the detonating type adapted to be ignited by the filament.` A cap 32 may close the inner `end of the case. To minimize the possibility of shorting the filament, the interior of the case 26 may be coated with a thinlayer of lacquer or other suitable material, not shown.l j Thehead 21 of the case 26 has suiiicient thickness to withstand `the external nuid pressures, and maybe convexed outwardlyto increase its strength. `'I'he conductor cord may havemolded plug portions 33 adapted to iill the counterbores 29 and form fluid seals for the cases 26.

` In the embodiment shown in Fig; `3, a cartridge 35 is employed.` This cartridge is in the form of an externally threaded sealed capsule containing as in theiirst construction,` an vexplosive charge 3| and anlament 30. In this construction,` one end ofthe iilament is; grounded to a wall of the `capsule while the other is connected to an insulated terminal 35 provided in one end of the` capsule.

The capsule is adapted to screwthread into a bore 20. The socket is the counterbore' `29 and material `is employed to seal theiexternal `flange ,s `oi the end Illinplace. A terminal element 39 is provided in the I the terminal 35.

flanged end 33 for engagement by 'I'he terminal element is con` nected `to a lateral lead I3c fromthe conductor I3. `In this constructionconductor |3b is con-` tinuous and :the several filaments are connected in parallel as eachforms a grounding connection from the conductor |3b to the gun body.1

Although the conductor cord I lis shown as passing over the muzzle ends of thegun chambers,it is of course feasible to place` the conductor cordatone side of the gunchambers and merely the lateral `leads llc; s

In thevforegoing constructions, the gun bores are isolated" from external pressure byseals at 75 tting within the gun provided with a hanged ment shown in Fig. 4. `Here the cartridge 4| is' in the form of a sealed capsule capable of with- -standing the crushing` force of the liquid in which the gun perforator may be immersed, and as in the previous constructions the cartridge 4I contains an explosive charge 3| and a filament 30 grounded at one end. The other end is connected directly to the lateral lead llc which exe tends into the capsulethrough a suitably sealed and insulated opening. Contact and spacer springs I2 `provide a grounded ,electrical contact between the cartridge,"` and the wallsof the gunbore as well as spaces the cartridge, so that 2|). The case 26 `may be molded or otherwise sesocket members may cupped at its outer s Because of the diiferent mode of sealing, the

`eral leads such well fluids as may enter the gun bore can flow between the cartridge and bullet. A sealing plug 43 of rubber or `other suitable material covers `the bullet. The `plug 43 preferably end to form sealinglipsu.

counterbore 2S may be omitted.

In the modification illustrated in Fig. 5,r a,

cartridge `5I is provided which is similar tothe cartridge 4I but is threadedto fit a socket member 52.` The socket member 52 may be formed of rubber or the like and is provided with a closed concave `outer end adapted to form a slidable sealing connection in s be moldedy integrally with forming ends for the 1at` |3c.` With this arrangement the lai;-` are made suihciently long to` permit rearward movement of `the the `conductor cord I3 eral leads s in the outer end of the bore as shown in Fig. 5.

` factors, to wit:` s

(1) The explosion of thepropellent charge is` inthe nature of a detonation, characterized by a faster rate of combustion thanthat which ment or by Thesocket memhery52 is provided with a terminal 53 which engages a terminal 5l provided in an end wall of the cartridge 5| `and to which one end of the filament 3| is connected. The other end of the filament 3| is grounded to the cartridge and the cartridge is grounded to the walls of the` gun bore 2|! bya spring clip 55 provided at the inner end of the cartridge.` The spring clip may also serve as a reinforcing to prevent crushingof the cartridge when.forced:against` the bullet by uid pressure before firing.` Y

In theoperation of the gun perforator, it is lowered intothe bore hole to the desired elevation while suspended fromthe cable I, whereupon a `circuit is electric current through Ithe conductor embedded in the cable 8, the electrodes III and I2, the conductor `I3 and the branchleads to each of the laments 3| to detonate the explosive charges in front of the bullets. The resulting concussion forces `thebullets rearwardly in the gun bores with suilicient force to'explode the propellent charges 22 and thusdischarge the bullets from the bores. This method of explodingthe `propellent charges `results in` a substantially higher` muzzle velocity oi' the bullets than` isthe case whenzthe charges areignited by aheated tlla- I the flame from a primer cap. 'I'he r of la higher muzzle velocity is beattainment lieved` to be due ,toa` combination of several occurs whenit is explodedbyignition.

(2) The pressure wave produced by the detonation of the explosive charge infront of the bullet momentarily retards the outward `movethe gun bore 2l. The

sockets 52 into the i gun bores, the excess length of lead being coiled established from a source of 8 ment of the bullet, allowing the pressure behind the bullet to increase to a high magnitude before the bullet starts to move.

(3) As the bullet is discharged, the space in front of the bullet is illled with gas from the explosion of the charge in front of the bullet, instead of being filled with liquid as in the usual case. and hence the resistance to movement of the bullet is greatly reduced. i

Aside from the advantages of the herein-d scribed gun perforator from the standpoint `of effectiveness in perforating casing, it possesses other desirable features. It is of simple construction and hence comparatively inexpensive to manufacture. The novel firing system facilitates assembly of the gun, both in the shop and when reloading at the site of operation. The conductor I3 with its branch leads and cartridges 2i, etc., may be made up as units and tested electrically and for fluid leakage before being applied to the gun.

While I have shown the novel firing system as applied to a gun periorator embodying removable and replaceable gun chambers, it `will be obvious that it is equally applicable to a gun perforator wherein the gun bores are formed directly in the gun body, as in the aforementioned copending application of Raymond D. Elliott, 'Serial No. 558,581. It will also be apparentthat the explosive means in front oi the bullets may assume other forms than those depicted, and hence the invention is not limited to the specific embodiments shown and described, butis of the full scope of the appended claims.

I claim: t

1, In a gun perforator, a gun body structure denningag1mbore;abulletinsaidgunbore:

propellent explosive means rearwardly of said bullet; sealing means in said gun bore in front of said bullet; and a duid-tight cartridge in said bore in front of said sealing means. said eartridgel containing an explosive charge and an electric ignition means therefor.

2. A gun perforator comprising: a gun bod having a gun bore therein; a propelling charge and bullet in said gun bore; a sealing means for the muzzle end of said gun bore; a threaded socket member extending into said gun bore from said sealing means an ignition cartridge threaded into said socket member and containing an explosive charge and an electric ignition means therefor; and a conductor means entering thek muzzle end of said gun bore and including contact terminals in said socket member and said cartridge for supplying electric current to said ignition means.

3. A construction as set forth in claim 2 wherein said gun bore is counter-bored at its muzzle end and said socket membex` includes a shoulder ntting said counter bore to restrain the socket member against inward movement.

4. A construction as set forth in claim 2 wherein said sealing means and socket member are an integral unit slidable in said .gun bore and said cartridge includes a grounding contact forming a reinforcing for supporting said oartridge on the outer end of said bullet when said gun body is submerged.

ALLEN E. HAMBLY.

vNo references cited.l 

